A tritium analysis model for the fusion-based hydrogen production reactor FDS-III blanket system was developed, including the High Temperature Liquid (HTL) blanket and major components of the auxiliary system (such as TES, CPS, and HX etc.). Based on the model, tritium safety assessment on HTL blanket system was done by using the Tritium Analysis Software (TAS), in which various factors affecting tritium permeation were considered,. The results showed that most of the tritium released into the environment would permeate through the heat exchanger as HTO. And a reasonable compromise among the various requirements could be found to keep the tritium released from HTL blanket system under safety guide line, based on the fabrication technology of the He/H2O heat exchanger, the capability of vent detritiation system, etc.